<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <script src="jquery-3.4.1.js"></script>
</head>
<body>
   <div>111</div>
   <input type="text" name="" id="uname">
   <button></button>
   <script>
       $('button').click(function(){
           $('div').html('<h2>1234123</h2>')
           //$('div').text('123123')
       })
       $('uname').val('12314141')
   </script> 
</body>
</html>